1. Field of the Invention
This invention relates to switching devices and, more particularly, to an interleaved differential switching apparatus.
2. Description of the Related Art
Typically, a traditional 2-wire differential switch module is used to test circuits that include several devices under test (DUTs) linked in series, such as battery stacks and fuel cell stacks. Traditional 2-wire differential switch modules usually include 2-wire channels that connect to common nodes between the DUTs. In this design, the two wires of each channel connect to a common node between two of the DUTs; therefore, each of the common nodes has two redundant connections.
The 2-wire channels are typically implemented using double-pole, single throw (DPST) switches, which means that two switch contacts are controlled by a single coil and cannot be operated independently. When switching from testing one DUT to another, the two switch contacts corresponding to the active 2-wire channel need to be deactivated, and then two other switch contacts corresponding to another 2-wire channel need to be activated. Since DPST switches are used, each 2-wire channel in this configuration requires 2 switch contacts. Therefore, traditional 2-wire differential switches may contain redundant switch contacts, which increase the size and cost of the switch module.
Many other problems and disadvantages of the prior art will become apparent to one skilled in the art after comparing such prior art with the present invention as described herein.